Chem. J. Chinese Universities ›› 2018, Vol. 39 ›› Issue (9): 1927.doi: 10.7503/cjcu20180075

• Analytical Chemistry • Previous Articles     Next Articles

Critical Factors Affecting Noncovalent Interaction Between Pentapeptides Explored by Electrospray Ionization Mass Spectrometry

WU Fangling, CHU Yanqiu*(), CHEN Xin, WEI Wanghui, DING Chuanfan*()   

  1. Department of Chemistry, Fudan University, Shanghai 200433, China
  • Received:2018-01-22 Online:2018-09-07 Published:2018-06-11
  • Contact: CHU Yanqiu,DING Chuanfan E-mail:chuyq@fudan.edu.cn;cfding@fudan.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No. 21773035).

Abstract:

The noncovalent interactions between two of the four pentapeptides including His-Val-Phe-Arg-Lys(HK), Ile-Tys-Lys-Val-Glu(IE), Val-Glu-Gly-Ile-Tyr(VY) and(Ala-Thr-Leu-Leu-Ser)(AS) were investigated by electrospray ionization mass spectrometry. The mass spectra show the formation of 1-1 complex by two of the four pentapeptides. The competitive reaction shows mass spectrometric signal for the complex of AS with VY and the complex of IE with VY are more stronger when the four pentapeptides were mixed together. The binding affinities of the complexes were determined by collision induced dissociation(CID) through survival yield vs. collision energy curves. The collision energy(CE50%) order is AS-AS(12.9 eV)~HK-VY(12.8 eV)?IE-IE(18.6 eV)~HK-IE(19.7 eV)~AS-VY(20.7 eV)~IE-VY(20.3 eV)?AS-IE(23.1 eV)~VY-VY(22.3 eV), indicating that the binding affinities of the complexes are apparently affected by side-chain group R of the amino acid residue composing of pentapetides, that is, the binding affinities of the complexes will be stronger with increasing the polarity and basicity of the side-chain R of amino-acid residue. The main driving force for the formation of the complexes should be ionic such as hydrogen-bonding, but not hydrophobic. The satistics of CE50% for the complexes of amino acids which can composed of four pentapeptide samples were plotted, which further confirmed the conclusions based on CID.

Key words: Pentapeptide, Electrospray ionization mass spectrometry, Noncovalent interaction, Influence factor, Collision induced dissociation

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